mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-22 12:14:01 +08:00
edb09eb17e
Large tc dumps (tc -s {qdisc|class} sh dev ethX) done by Google BwE host
agent [1] are problematic at scale :
For each qdisc/class found in the dump, we currently lock the root qdisc
spinlock in order to get stats. Sampling stats every 5 seconds from
thousands of HTB classes is a challenge when the root qdisc spinlock is
under high pressure. Not only the dumps take time, they also slow
down the fast path (queue/dequeue packets) by 10 % to 20 % in some cases.
An audit of existing qdiscs showed that sch_fq_codel is the only qdisc
that might need the qdisc lock in fq_codel_dump_stats() and
fq_codel_dump_class_stats()
In v2 of this patch, I now use the Qdisc running seqcount to provide
consistent reads of packets/bytes counters, regardless of 32/64 bit arches.
I also changed rate estimators to use the same infrastructure
so that they no longer need to lock root qdisc lock.
[1]
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kevin Athey <kda@google.com>
Cc: Xiaotian Pei <xiaotian@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
69 lines
2.3 KiB
C
69 lines
2.3 KiB
C
#ifndef __NET_GEN_STATS_H
|
|
#define __NET_GEN_STATS_H
|
|
|
|
#include <linux/gen_stats.h>
|
|
#include <linux/socket.h>
|
|
#include <linux/rtnetlink.h>
|
|
#include <linux/pkt_sched.h>
|
|
|
|
struct gnet_stats_basic_cpu {
|
|
struct gnet_stats_basic_packed bstats;
|
|
struct u64_stats_sync syncp;
|
|
};
|
|
|
|
struct gnet_dump {
|
|
spinlock_t * lock;
|
|
struct sk_buff * skb;
|
|
struct nlattr * tail;
|
|
|
|
/* Backward compatibility */
|
|
int compat_tc_stats;
|
|
int compat_xstats;
|
|
int padattr;
|
|
void * xstats;
|
|
int xstats_len;
|
|
struct tc_stats tc_stats;
|
|
};
|
|
|
|
int gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
|
|
struct gnet_dump *d, int padattr);
|
|
|
|
int gnet_stats_start_copy_compat(struct sk_buff *skb, int type,
|
|
int tc_stats_type, int xstats_type,
|
|
spinlock_t *lock, struct gnet_dump *d,
|
|
int padattr);
|
|
|
|
int gnet_stats_copy_basic(const seqcount_t *running,
|
|
struct gnet_dump *d,
|
|
struct gnet_stats_basic_cpu __percpu *cpu,
|
|
struct gnet_stats_basic_packed *b);
|
|
void __gnet_stats_copy_basic(const seqcount_t *running,
|
|
struct gnet_stats_basic_packed *bstats,
|
|
struct gnet_stats_basic_cpu __percpu *cpu,
|
|
struct gnet_stats_basic_packed *b);
|
|
int gnet_stats_copy_rate_est(struct gnet_dump *d,
|
|
const struct gnet_stats_basic_packed *b,
|
|
struct gnet_stats_rate_est64 *r);
|
|
int gnet_stats_copy_queue(struct gnet_dump *d,
|
|
struct gnet_stats_queue __percpu *cpu_q,
|
|
struct gnet_stats_queue *q, __u32 qlen);
|
|
int gnet_stats_copy_app(struct gnet_dump *d, void *st, int len);
|
|
|
|
int gnet_stats_finish_copy(struct gnet_dump *d);
|
|
|
|
int gen_new_estimator(struct gnet_stats_basic_packed *bstats,
|
|
struct gnet_stats_basic_cpu __percpu *cpu_bstats,
|
|
struct gnet_stats_rate_est64 *rate_est,
|
|
spinlock_t *stats_lock,
|
|
seqcount_t *running, struct nlattr *opt);
|
|
void gen_kill_estimator(struct gnet_stats_basic_packed *bstats,
|
|
struct gnet_stats_rate_est64 *rate_est);
|
|
int gen_replace_estimator(struct gnet_stats_basic_packed *bstats,
|
|
struct gnet_stats_basic_cpu __percpu *cpu_bstats,
|
|
struct gnet_stats_rate_est64 *rate_est,
|
|
spinlock_t *stats_lock,
|
|
seqcount_t *running, struct nlattr *opt);
|
|
bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats,
|
|
const struct gnet_stats_rate_est64 *rate_est);
|
|
#endif
|